This invention is directed to a method for manufacturing composite plastic articles and the plastic articles themselves which carry finely detailed icons on outer surfaces thereof. The plastic articles made by the method of this invention may include such diverse items as knobs; vehicle, machinery, equipment and appliance control panels and buttons for such panels. The invention includes plastic articles having icons that are visible in reflective light and can also be backlighted for installation in knobs, panels and buttons in vehicles where the icons must be visible during the daylight and at night. The term "icon", as used in this specification and claims, refers not only to functional representational images of the type commonly used in the computer world but also includes letters, numerals, indicator lines, trademarks, logos and symbols of all shapes and sizes which may be perceived by the human eye.
Conventionally, the manufacture of the aforementioned types of knobs, control panels and buttons has required multiple, labor intensive operations. Such operations have included the silk screening of icons on films and the lamination of the films to injection molded plastic parts. Another conventional technique has involved the use of lasers to remove portions of painted coatings from plastic cores to create icons. These labor intensive operations have been considered necessary in order to produce knobs, control panels and buttons having icons of sufficiently fine detail and clarity.
An object of this invention is the manufacture of composite plastic articles having at least one icon which articles can be made entirely from injection molded plastic components.
Another object of this invention are composite plastic articles formed of injection molded components having backlightable icons which are molded to a high degree of definition and clarity.
Still another object of this invention are composite plastic articles having icons provided on non-planer surfaces and particularly on compound curved surfaces.
Yet another object of this invention is a composite plastic article having an icon formed of an extremely thin layer of translucent plastic and supported by an anvil of a light transmitting plastic during finishing operations involving the injection molding of an outer covering.
An additional object of this invention are composite plastic articles having icons positioned on curved surfaces which icons are proportioned so as to be legible in spite of their location on a non-planer surface.
Still an additional object of this invention is a method of injection molding a composite plastic article having an integral icon which matches or exceeds in clarity and in detail icons made by silk screening or laser-paint processes.
Other objects may be found in the following specification, claims and drawings.